The invention relates to a method for manufacturing a cup from a conical sleeve and a pot-shaped base, wherein the base has a base face and a circumferential wall starting from the base face, and is inserted from a relatively large opening in the conical sleeve into the sleeve in the direction of the relatively small opening in the sleeve. The invention also relates to a device for manufacturing a cup from a conical sleeve and a pot-shaped base, wherein the device is designed to insert the base from a relatively large opening in the conical sleeve into the sleeve in the direction of the relatively small opening in the sleeve.
In known methods for manufacturing a cup and in known devices, problems can occur when inserting the pot-shaped base into the conical sleeve if during the insertion the base sticks against the inner side of the sleeve and as a result impedes correct positioning of the base in the sleeve. This can occur, for example, if the base and/or the sleeve are already coated with adhesive, if, for example, the material of the base and/or of the sleeve is sticky also merely owing to the ambient temperatures, or there is a high coefficient of friction at least between the base and the sleeve. It is problematic here that owing to the conical sleeve and the subsequent fluid-tight pressing of the base and sleeve, the base has to be placed in a position inside the sleeve in which it inevitably bears against an inner wall of the sleeve. Otherwise, it is not possible to press the base against the sleeve.
The invention is intended to improve a method and a device for manufacturing a cup from a conical sleeve and a pot-shaped base.
According to the invention, there is provision for at least partially covering a radially outer circumferential face of the wall of the pot-shaped base with an annular covering sleeve, arranging the covering sleeve and the base in a predefined relative position between the sleeve and the base, pulling out the covering sleeve between an inner side of the sleeve and the radially outer circumferential face of the base, wherein the base remains in the predefined relative position, and connecting the radially outer circumferential face of the base and the inner side of the sleeve in an essentially fluid-tight manner. According to the invention, an annular covering sleeve is therefore arranged between a radially outer circumferential face of the wall of the pot-shaped base and the inner side of the sleeve. Therefore, when the base is placed in position only the outer side of the covering sleeve comes into contact with the inner side of the sleeve. The outer side of the covering sleeve can be selected here with respect to the material or the surface in such a way that the covering sleeve can slide in an easily moving fashion on the inner side of the sleeve. The covering sleeve is not pulled out between the circumferential wall and the inner side of the sleeve until the base has reached a predefined relative position with respect to the sleeve. At this point, the base and the sleeve are located relative to one another but already at rest and at the predefined relative position. Possible sticking of the base and sleeve in this position is therefore undamaging and even desired during the subsequent step of fluid-tight connection. The invention therefore achieves in a surprisingly simple way a considerable improvement in a method for manufacturing a cup. Within the scope of the invention, the covering sleeve can be placed together with the base into the sleeve or the covering sleeve can be stationary in relation to the sleeve and the base can be pushed into the covering sleeve. The method according to the invention has particular advantages if owing to the materials of the base and sleeve there is a risk of the base sticking against the sleeve during a relative movement with respect to one another. The invention is therefore particularly designed for materials whose surfaces have a high coefficient of friction with respect to one another. This material can be, for example, coated paper material or coated pulp, for example but can also be a planar plastic material which can be processed in a similar manner to paper. Planar plastic materials are, for example, also plastic laminates. The invention is very well suited here for plastic material which can be processed in a similar manner to paper, but is not specifically designed for plastic material which can be processed in a similar manner to paper.
In a development of the invention, the predefined relative position corresponds, at least when viewed in the longitudinal direction of the sleeve, to the relative position of the base and sleeve on the finished cup.
In this way, the base and sleeve no longer have to be moved relative to one another after the covering sleeve has been pulled out between the circumferential wall of the base and the inner side of the sleeve. Slight sliding during the fluid-tight connection of the base and sleeve are accepted from this.
In one development of the invention, in the predefined relative position an outer circumferential face of the covering sleeve bears at least in certain sections against the inner side of the sleeve or is arranged directly adjacent to the inner side of the sleeve.
In this way, the circumferential wall of the base and the inner side of the sleeve can be moved very close to one another without being directly in contact. For example, the base can be arranged with slight prestress in the covering sleeve, with the result that after the pulling out of the covering sleeve the circumferential wall widens slightly and then the circumferential wall of the base bears in a planar fashion against the inner side of the sleeve.
In one development of the invention, there is provision for the covering sleeve to be positioned together with the base in the direction of the relatively small opening in the sleeve until the predefined relative position is reached.
According to the invention, the device for manufacturing a cup from a conical sleeve and a pot-shaped base is designed to insert the base from a relatively large opening in the conical sleeve into the sleeve in the direction of the relatively small opening in the sleeve. The device has an annular covering sleeve whose inner circumference is so large that a circumferential wall of the pot-shaped base bears against the inner circumference. Furthermore, the device has an apparatus for moving the covering sleeve in and counter to a longitudinal direction of the sleeve and an apparatus for securing the base in a predefined relative position with respect to the sleeve when simultaneously pulling out the covering sleeve between the inner side of the sleeve and the circumferential wall of the base. With the device according to the invention, the manufacture of a cup from a conical sleeve and a pot-shaped base is considerably facilitated, in particular when the materials or the surfaces of the base and sleeve have a high coefficient of friction with respect to one another and therefore there is a risk of the base sticking on the sleeve during a relative movement. This can occur, for example, with paper material which is coated in a fluid-tight fashion or also with plastic materials which are to be processed in a similar manner to paper.
In one development of the invention, a die for securing the base is provided, wherein the die has an activation rod and a die face which bears against the base, the covering sleeve being arranged in such a way that it can be slid on the activation rod of the die.
In this way, the covering sleeve can, for example, be arranged precisely concentrically with respect to the activation rod and also reliably guided during the pulling out of the covering sleeve between an inner side of the sleeve and the radially outer circumferential face of the base. The device according to the invention can as a result achieve high speeds and therefore short cycle times during the manufacture of cups.